Ultrasonics have been utilized for many years in a variety of diagnostic, therapeutic, and research purposes. Some uses of ultrasonic or acoustic energy in materials processing include breaking up and/or mixing of fluid suspensions of materials. Additional uses are in solubilizing or otherwise ensuring that all or substantially all of the constituents of a sample are in solution and/or in suspension. Regardless of the particular use, sample materials are typically contained in a plastic or glass enclosure, such as vials, tubes, culture plates/well, or micro-titer plates, with an acoustic transducer coupled to the sample by way of a coupling medium, such as water. Typically, systems in which acoustic energy is precisely controlled and transferred to a sample in a vessel are relatively low power. Examples of low power systems include high-frequency, low-intensity focused acoustic dispensing systems, which transfer droplets of sample from a fluid-air interface through an air gap to a receiving vessel, and high-frequency focused interrogation systems commonly used in non-destructive testing of materials. Alternatively, acoustic transducers can be directly immersed in the material to be treated. This type of system, in which an acoustic transducer directly contacts the sample, is capable of relatively high power; however, it is typically of lower frequency. A distinct disadvantage of lower frequency systems is the lack of control inherent with long wavelength acoustics. For example, the low-frequency probe-type sonicator typically used in biological and chemical laboratories is operated at approximately 15 KHz, which results in wavelengths in aqueous media measuring several centimeters. Other systems can implement both high-power and high-control processing of diverse samples. However, there exists a need for a system with both high-power and high-control which is easy to use on a routine basis with minimal a priori sample preparation, process optimization, or operator training.
The foregoing arrangements have been used for a number of applications, including large-scale batch processing, yet there is still a need for acoustic systems and methods that are more flexible, convenient, and effective, in particular for on-demand uses, such as for automated processing of small quantities of samples, for example, in laboratory or benchtop settings.